1. Field of the Invention
The present invention relates generally to apparatus that are used to provide temporary electrical power to construction sites. Particularly, the present invention relates to a portable apparatus for providing temporary electrical power to a construction site. The present invention also relates to methods of providing temporary electrical power to construction sites by using the apparatus.
2. State of the Art
A temporary source of electricity is typically needed at a construction site to power electrical tools, lighting, and other equipment that may be used at the construction site. Temporary power is often provided to a construction site by way of a temporary connection to either an overhead or underground power supply.
When electricity is provided to a construction site by way of a temporary connection to an overhead power supply, an electrician typically has to dig a hole and set a cumbersome temporary service pole close to a transformer associated with the overhead power lines. Digging the hole and securing, or setting, the temporary service pole therein is often a labor-intensive, time-consuming task, as the hole must be deep enough to secure the typically tall, temporary service pole for the entire duration of construction at the site.
Typically, a temporary service pole has a conduit along at least a portion of the length thereof. Service wires extend from the top of the temporary service pole, through the conduit, to a location along the length of the temporary service pole where a meter base, which measures the amount of electricity used at the construction site, is to be secured. Thus, the conduit of the temporary service pole encloses the electrical wires to protect and prevent tampering with the service line.
The electrician connects the ends of the wires of the service line that are exposed along the length of the temporary service pole to a meter base. The meter base is electrically connected to a breaker box to which one or two electrical receptacles that are protected by a ground fault circuit interrupter (GFCI) are typically electrically connected. The meter base, breaker box, and conduits are then secured to the temporary service pole. Once the temporary service pole is in place, the local inspection authority will inspect the pole and the wiring between each of the foregoing components. The power company then connects the other end of the wires of the temporary service line to the nearby overhead power supply.
A temporary hookup can be made to underground power lines in a similar manner. If a temporary service pole is used to provide power to a construction site from an underground power supply, however, the wires of the service line extend through the pole to a location proximate the bottom end thereof to facilitate connection with the underground power lines. Alternatively, as long as the service line is somehow enclosed and protected, the service pole can be omitted and the temporary service line connected directly to a stable, stationary meter base.
Since it typically takes several months to complete the construction of a structure, electricians typically include the costs of temporary electrical service components in their fee for setting up the temporary electrical connection. Moreover, the components of a temporary electrical connection, including the service line, the meter base, and the breaker box, can be exposed to a variety of weather conditions, as well as construction conditions that may damage these temporary electrical service components. If the components of the temporary electrical connection are to be reused, once construction has been completed the components must be disassembled from one another and the temporary service pole removed from the ground. These components, including the cumbersome temporary service pole, are then typically loaded onto or in a trailer and transported to another construction site or stored for later use. Electricians sometimes abandon the components of a temporary electrical connection.
Once temporary electrical service has been provided to a site, long extension cords are typically required to convey power from the fixed location at which the temporary electrical service is provided to locations of the site that are remote from the location of the temporary electrical service. When multiple extension cords are hooked up to temporary electrical service, these cords may become entangled with one another or present workplace tripping hazards that are equal in number to the number of cords that extend across a portion of a work site.
Accordingly, there is a need for an apparatus by which temporary electrical service can be provided without requiring an electrician to dig a hole, to set a temporary service pole in the hole, to electrically connect a meter base to one end of a service line, and to electrically connect a breaker box to the meter base. There are also needs for an apparatus that enables an electrician to reuse the components of a temporary electrical connection without removing a temporary service pole from the ground or requiring the disassembly of each of the components, for a temporary electrical service apparatus that can be more easily moved from one construction site to another, and for an apparatus that can be used, without significant modification, to provide temporary electrical service from either overhead or underground power lines. In addition, there is a need for a system by which electricity may be distributed at locations remote from such a temporary electrical service apparatus.
The present invention includes an apparatus for providing temporary electrical service, for example, at a construction site. The apparatus of the invention includes a support structure having an enclosed service line, a meter base, a breaker box, and electrical receptacles. The service line is prewired to the meter base, which is prewired to the breaker box. Electrical receptacles that are protected by a ground fault circuit interrupter (GFCI) are electrically connected to the breaker box.
According to a first aspect of the invention, the apparatus has a portable support structure, such as the bed of a trailer. Thus, the apparatus has wheels to facilitate the ready transport thereof from one construction site to another construction site or to a storage location. A portion of the service line extends through an enclosure of the support structure, such as a conduit through or secured to the trailer. One end of the service line is exposed for connection to a power supply. The other, enclosed end of the service line communicates electrically with the meter base, which is secured to the trailer. The meter base, in turn, communicates electrically with the breaker box, which is also secured to the trailer. In addition, electrical receptacles may be secured to the trailer.
In another aspect of the present invention, the apparatus may be used to provide temporary electrical service from either an overhead power supply or an underground power supply.
Such an apparatus has secured to the support structure a service pole configured to facilitate the connection of a first service line to an overhead power supply. Preferably, the service pole is pivotally secured to the support structure so as to be movable between a lowered, transport position and an upwardly extending electrical service position. Preferably, the service pole may be secured in the electrical service position. An end of a first line is exposed proximate a top end of the service pole to facilitate connection of the first service line to an overhead power supply. The first service line extends through and is enclosed within the service pole and through an enclosure of the support structure to a transfer switch secured to the support structure.
The apparatus also includes a second service line. A first end of the second service line is configured to be connected with an underground power supply. The second service line extends through an enclosure of or is carried by the support structure to the transfer switch.
The transfer switch has three positions: a first position that permits the transfer of electricity from the first service line therethrough; a second position that permits electricity from the second service line to flow therethrough; and a third position in which both service lines are open and no electricity passes through the transfer switch. Depending upon the position of the transfer switch, electricity from one of the first and second service lines may flow to the meter base through a transfer line connected between the transfer switch and the meter base. Electricity then flows to the breaker box, which is connected to the meter base, and may be used by way of receptacles that are in electrical communication with the breaker box. Moreover, as the first and second service lines are connected to the transfer switch in such a manner that electricity from only one of the service lines flows through the switch, the first and second service lines remain electrically isolated from each other. Therefore, when one of the first and second transfer lines is connected to a power supply, electricity will not flow to the exposed end of the other transfer line (i.e., the exposed end of the other transfer line will not be live).
The present invention also includes apparatus that provide electrical service at locations that are remote from the fixed locations at which temporary electrical service is provided. These remote electrical service apparatus may be portable to facilitate movement thereof to various locations.
An exemplary remote electrical service apparatus incorporating teachings of the present invention includes a frame which carries an electrical cord for establishing communication between a temporary electrical service apparatus, such as that disclosed herein, at a relatively fixed location and the electrical components of the remote electrical service apparatus. The electrical cord may communicate with a breaker box which includes one or more breakers that, in turn, communicate with one or more receptacles. Alternatively, the electrical cord may communicate directly with one receptacle, or with a number of different receptacles by way of branches therefrom.
The remote electrical service apparatus may also include a storage component for stowing all or portions of the electrical cord. For example, when the remote electrical service apparatus is in use, a portion of the length of the electrical cord that is not needed to establish an electrical connection between the remote electrical service apparatus and a fixed temporary electrical service location may be stowed by the storage component. When the remote electrical service apparatus is not being used, the entire electrical cord may be received by the storage component.
Wheels may be used to impart portability to remote electrical service apparatus of the present invention.
The present invention also includes methods using the apparatus to provide temporary electrical service from either an overhead power supply or an underground power supply, as well as methods for disconnecting the apparatus from a power supply and transporting the apparatus to another location for reuse or storage. In addition, the present invention includes systems and methods for distributing electricity from the location of the apparatus to other locations of the site that are remote from the apparatus.
Other features and advantages of the present invention will become apparent to those in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims.